As @matburt has already explained, it is technically impossible to remove an account due to the attached game records, which cannot reasonably be taken away from the opponents’ profiles.
It is also a nonsensical function, because the user can simply erase all information associated with the account, including the account name itself, leaving nothing but an abstract shell with a user id.
That being said, maybe this is a case in which some users will feel better if they just have “something there” that they can click, with a nice message that says “your account is no longer”, which they can print out and stick in a photo frame.
You could accurately name this function “Close Account”.